# How do balanced chemical equations relate to the law of conservation of mass?

Jan 1, 2016

Chemical reactions involve the rearrangement of atoms, entities of definite mass. Chemical equations represent these reactions.

#### Explanation:

So if I start with 10 g of reactant (from all sources) AT MOST I can get 10 g of product. In practice, I can seldom get even that.

In the same way, if I burn 12 g of carbon in the presence of 32 g of oxygen AT MOST I can get 44 g carbon dioxide.

We can represent this by a simple chemical equation, in which equivalent masses are implicit:

$C \left(s\right) + {O}_{2} \left(g\right) \rightarrow C {O}_{2} \left(g\right)$

Each atom and each molecule have definite masses. So mass is conserved in EVERY chemical reaction. Is it conserved in every NUCLEAR reaction?